高质量信道上回声隐藏法秘密信息提取出错原因分析

Analysis on error reasons of secret information extraction in high quality channel by echo hiding method

回声信息隐藏是通过在载体语音中嵌入不同延时的回声来实现信息隐藏的一种技术。介绍回声隐藏算法的基本原理,分析回声隐藏法秘密信息提取的关键步骤,即计算隐藏秘密信息后语音的倒谱,并结合线性卷积与循环卷积的关系,推导及总结了在高质量信道上利用回声隐藏法进行隐蔽通信时秘密信息提取出错的原因。分析表明,实际应用中可根据语音在延迟处的倒谱值自适应地调节回声衰减因子的大小,提高回声隐藏法秘密信息恢复的准确率。

Echo information hiding is a technique to realize information hiding by embedding different delay echoes in carrier voice. The basic principle of echo hiding algorithm is introduced. The key steps of secret information extraction with echo hiding method is analyzed,that is the voice cepstrum after calculating the hiding secret information. According to the relation of linear convolution and cycle convolution,the error reasons of secret information extraction when the hiding communication is imple-mented with echo hiding method in high quality channel are deduced and summarized. The accuracy of secret information recovery with echo hiding method is improved by regulating the size of echo decay factor adaptively according to the cepstrum value in delay areas of the voice.